CE/ESR 410/510
TESTING THE TOXIC CHARACTERISTICS OF CHEMICALS
U.S. EPA, Office of Prevention, Pesticides and Toxic Substances (OPPTS)
Under the Toxic Substance Control Act (TSCA), EPA has broad authority to issue regulations designed to gather health/safety and exposure information on, require testing of, and control exposure to chemical substances and mixtures. Drugs, cosmetics, foods, food additives, pesticides, and nuclear materials are exempt from TSCA and are subject to control under other U.S. Government statutes (e.g., foods, food additives, drugs and cosmetics are under the purview of the Federal Food, Drug, and Cosmetic Act (FFDCA) administered by the U.S. Food and Drug Administration (FDA); pesticides fall under the EPA-administered Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA)). TSCA has differing mandates regarding the regulation of "existing" chemicals (i.e., those already in U.S. commerce) and "new" chemicals (i.e., those not yet in U.S. commerce). Therefore, when TSCA became effective on January 1, 1977, it was imperative that EPA be able to distinguish between existing chemicals and new chemicals. This was accomplished by way of TSCA Section 8(a) information reporting requirements that resulted in the creation of the TSCA Chemical Substances Inventory.
In simple terms, the TSCA Inventory is a compilation of the names of all existing chemical substances along with their respective Chemical Abstract Service (CAS) Registry numbers, production/importation volume ranges, and specific sites of production/importation. EPA's TSCA Inventory currently contains over 70,000 existing chemicals, many of which are produced or imported at low or negligible volumes, while others are polymers which, because of their size (e.g., high molecular weight) and other characteristics, are unlikely to present significant risk concerns. If one excludes low volume chemicals (~25,000 chemicals produced or imported in amounts less than 10,000 pounds per year) and polymers (which tend to be poorly absorbed by organisms and therefore exhibit low toxicity), one finds that there are about 15,000 non-polymeric chemicals produced/imported at levels above 10,000 pounds per year. Of these levels above 1 million pounds the High Production Volume or "HPV" chemicals). The 15,000 chemicals subset has been identified as being within the broad focus of OPPT's Existing Chemicals and Chemical Testing Programs with the primary focus being on the 3,000-4,000 HPV chemicals.
The TSCA test guidelines are based on the harmonized test guidelines in the unified library for test guidelines issued by the Office of Prevention, Pesticides and Toxic Substances (OPPTS) for use in testing chemical substances to develop data for submission to EPA under TSCA, the Federal Food, Drug, and Cosmetic Act (FFDCA), and the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). "Harmonized" means that chemicals tested under any of these three laws will be subjected to comparable tests and standards. The process for developing and amending the harmonized test guidelines includes broad public participation and extensive involvement of the scientific community.
A. What are Test Guidelines?
Test guidelines are a standardized set of test procedures or protocols organized by health effect or other testing endpoint. These guidelines present generally formulated procedures for laboratory testing of an effect or characteristic deemed important for the evaluation of health and environmental hazards of a chemical. These guidelines are designed to, when followed, produce data which are accurate, reliable, and reproducible. Such data are necessary for the regulatory programs under TSCA.
B. What are TSCA Test Guidelines?
TSCA test guidelines are guidelines which were established to meet the regulatory needs of TSCA, particularly the needs of the TSCA section 4 testing program. The TSCA section 4 testing program is a regulatory program which is based on the promulgation of rules requiring certain persons identified in the rule, usually manufacturers and processors of the chemical to conduct testing of the chemical specified in the rule (Section 4(b)(1)(B) of TSCA).
C. How are TSCA Test Guidelines Used?
The Agency uses this system of standardized guidelines, organized by testing endpoint and codified in a subpart of this part for use in cross-referencing in a TSCA section 4 action. When a section 4 test rule is promulgated, the test rule cross-references the appropriate TSCA test guideline for the bulk of the testing requirements. In this context, the public is given notice of, and an opportunity to comment on, these guidelines as they are applied in chemical-specific test rules.
D. Where Did the TSCA Test Guidelines Come From?
The TSCA test guidelines series were first promulgated in 1985 (50 FR 39252, September 27, 1985) and were established in 40 CFR parts 795 through 798. The Agency has over time amended and improved these guidelines (52 FR19072, May 20, 1987) and in some cases revoked those guidelines which had not been cross-referenced in any test rules (60 FR 31917, June 19, 1995) (FRL–4955–2)). In 1991, EPA began an effort to blend the testing guidance and requirements that existed in the Office of Pollution Prevention and Toxics (OPPT) appearing in 40 CFR parts 795 through 798, the Office of Pesticides Programs (OPP) guidelines which appeared in publications of the National Technical Information Service (NTIS), and the guidelines published by the international Organization for Economic Cooperation and Development (OECD). The product of this effort would be one set of guidelines which would be thus blended or ‘‘harmonized.’’ These harmonized guidelines would then be made available to the EPA, other government agencies, and the public through the World Wide Web (Internet) and would be accessible by anyone with a personal computer and the ability to connect to the Internet. The EPA Internet web site would be the site and publication source for the ‘‘OPPTS Harmonized Guidelines’’ http://www.epa.gov/opptsfrs/home/guidelin.htm
E. How were these OPPTS Harmonized Test Guidelines Developed?
The OPPTS harmonized test guidelines for health effects endpoints were first drafted by EPA scientists for specific testing endpoints. These drafts were reviewed by other EPA experts and, in some instances, presented at domestic and international colloquia in order to solicit the views of recognized experts and the regulated community. These draft harmonized guidelines were made available on the Internet as public drafts and a notice was published in the Federal Register of June 20, 1996 (61 FR 31522) (FRL–5367–7) announcing the availability of these draft guidelines soliciting public comment.